Theo's Mind Palace

文章目录区别用处示例区别peek()无法修改返回值类型，map()可以修改返回数据类型，都会返回stream，peek()是接收Consumer表达式没有返回值，map()接收的入参是Function表达式，之前搜索的时候看到的都是说peek()没有返回，peek不接收返回根本不会执行。foreach()会中断流，很多操作需要再进行一次流处理。如先需要处理某属性的值，再根据条件筛选出需要的值，foreach()需要在修改后再进行一次流处理，如果是map()，就可以在不中断流的情况下连续处理。用处p

文章目录String处理1.join连接String处理1.join连接String[] strArr = {"wo", "shi", "sha", "bi"};String join = String.join(" ", strArr);System.out.println(join);wo shi sha bi

Java object to XML调别人接口，需要传xml格式数据，结构比较复杂需要效果<COUNTRY> <COUNTRY_NAME>CHN</COUNTRY_NAME> <LEVEL>SSS</LEVEL> <PROVINCE_LIST> <PROVINCE> <PROVINCE_NAME>浙江</PROVINCE_NAME&g

Collectors.removeIfdefault boolean removeIf(Predicate<? super E> filter)Removes all of the elements of this collection that satisfy the given predicate. Errors or runtime exceptions thrown during iteration or by the predicate are relayed to the ca

Stream.filter()Stream<T> filter(Predicate<? super T> predicate)Returns a stream consisting of the elements of this stream that match the given predicate.filter保留符合predicate的元素List<Student> studentList = new ArrayList<>();stude

streamCollectors.collectingAndThenAdapts a Collector to perform an additional finishing transformation对结果集收集的结果再用function函数进行处理，第一个参数是Collector，可以使用Collectors里面的各种工具类public static <T,A,R,RR> Collector<T,A,RR> collectingAndThen(Collector&l

List<Student> testList = new ArrayList<Student>();testList.add(new Student("张一", 1, 13, "3"));testList.add(new Student("张二", 2, 13, "4"));testList.add(new Student("张三", 3, 14, "4"));testList.add(new Student("老王", 4, 14, "2"));testList.add(

变量之间的比较int、Integer、string的比较public class Compare { public static void main(String[] args) { System.out.println("Compare of int"); int a = 12; int b = 34; int c = 46; int d = 46;